Wrinkle resistance treatment for cellulosic textile fabrics



United States Patent ice WRINKLE RESISTANCE TREATMENT FOR CELLULOSIC TEXTILE FABRICS Robert M. Reinhardt, John G. Erick, Jr., Richard L.

Arceneaux, and John D. Reid, all of New Orleans, La.,

assignors to the United States of America as represented by the Secretary of Agriculture N0 Drawing. Filed Mar. 23, 1959, Ser. No. 801,417

2 Claims. (Cl. 117-139.4) (Granted under Title 35, US. Code (1952), sec. 266) be laundered by procedures usually used with untreated textiles of the same type, which procedure can include the use of hypochlorite bleaching agents, without suffering additional damage because of the wrinkle resistance treatment.

Fabrics composed of cellulosic fibers, such as cotton,

rayon and the like have poor resiliency and consequently, when in use tend to become wrinkled and acquire a mussed or unpleasant appearance. In order to overcome this objectionable property, it hasbcen the practice to treat cellulosic fabrics with the methylol derivatives of organic nitrogen compounds, such as amine. Such treatments are indeed successful in improving the resiliency of the cellulosic fabric and so producing a resistance to wrinkling. The fabrics so treated, however, cannot be bleached by ordinary methods using a hypochlorite bleaching agent without suffering discoloration or severe loss in strength either in the bleaching operation or on subsequent ironing. This is a major objection to the use of these treatments, particularly on white cellulosic fabrics.

Recently, the methylol derivatives of some special organic nitrogen compounds have been used to avoid this rea, guanidine, or melobjectionable feature of the treatments. An example of this type compound is dimethylol ethyleneurea. This compound has been found to be effective in preventing any damage from the use of hypochlorite bleaching agents on fabric treated with it, and at the same time imparts a high degree of resiliency to the fabric. After repeated laundering, however, fabric treated with dimethylol ethyleneurea is susceptible to damage from the hypochlorite bleaching agents although the fabric retains its resiliency. In other words, the effectiveness of dimethylol ethyleneurea in preventing damage to the treated fabrics from hypochlorite bleaching agents is not durable although the resiliency imparted to the fabric is durable.

Another class of compounds that has been proposed for use in the treatment of cellulosic fabrics to improve their resiliency is polymeric acetals formed by the reaction of formaldehyde with polyhydroxy compounds. Fabric treated with these compounds has no tendency to suffer damage from exposure to hypochlorite bleaching agents. However, the improvement in resiliency imparted by these compounds is relatively small and, therefore, the treated fabrics have only a weak resistance to wrinkling or mussing.

We have found that cellulosic fabrics may be treated with a mixture of dimethylol ethyleneurea and the previously mentioned polymeric formaldehyde acetals to produce treated fabrics having a high degree of resiliency and a strong resistance to wrinkling and mussing, such as produced by treatment with dimethylol ethyleneurea alone. Fabrics treated with the aforementioned mixture do not suffer damage on hypochlorite bleaching. Surprisingly, this resistance to damage from hypochlorite bleaching agents is retained after repeated launderings, in spite of the presence of dimethylol ethyleneurea in the mixture used for the treatment. Furthermore, the original resiliency and strong resistance to wrinkling and mussing is also retained after the repeated launde'rings.

It is an object of this invention, therefore, to provide a process for the treatment of textile fabrics composed mainly of cellulose whereby the fabric obtains the properties of increased resiliency, wrinkle resistance, muss re-} sistance, and a shape-holding ability and which properties are retained after repeated laundering. It is furthermore an object of this invention to provide such a treatment whereby the treated fabrics, with the properties described, may be laundered by ordinary procedures, which procedures may include the use of hypochlorite bleaching agents, without suffering discoloration -or loss in strength in the laundering procedure or subsequent treatment greater than occurring on untreated fabric, and this ability is also retained after repeated laundering.

The objects of this invention are accomplished by the treatment of the cellulosic textile with an aqueous solution containing: (1) 3 to 7% of dimethylol ethyleneurea; (2) 5 to 10% of a polymeric acetal formed from formaldehyde and a polyhydroxy compound; and (3) l to 6% of an acidic condensation catalyst, which can either be an acidic substance or a substance that forms acids on heating, to promote condensation of the other components. A metal salt of a strong mineral acid is a particularly suitable acidic condensation catalyst to use in the process of the present invention.

Treatment of the textile according to the process of this invention comprises impregnating (thoroughly Wetting) the textile with the above-described solution, mechanically removing excess liquid, then drying and curing the goods. All of these steps can be conveniently carried out with conventional textile finishing equipment. The Wet pickup (increase in weight of the textile upon Wetting), after mechanically removing excess liquid, should preferably be from about to Adjustment to the desired wet pickup can be conveniently achieved by passing'the impregnated textile through squeeze rolls or the like. The drying time and temperature are not critical, but it is preferable to dry the wet textile, adjusted to the desired pickup, at relatively low temperature, from about 60 C. to C., until the textile is dry to the touch; After drying, the textile is cured by subjecting it to a higher temperature, from about to C., for a brief time, usually from about 3 to 6 minutes, to cause condensation of the applied materials. In the curing operation, the longer time is used with the lower curing temperature.

Following the curing operation, it is preferable to water-wash the treated textile to remove any remaining unreacted materials or objectionable byproducts of the condensation. The washing operation can be conveniently carried out using the procedures and equipment conventionally employed for the washing of textiles.

In addition to the dimethylol ethyleneurea, the polymeric formaldehyde acetal, and the acidic condensation catalyst, the treating mixture of this invention may also contain wetting agents, softening agents, thermoplastic polymeric additives such as polyethylenes, polyacrylates, silicones and the like, and other components commonly included in conventional wrinkle resistance treatments.

The process of this invention can be used to treat substantially any hydrophilic fibrous cellulosic material such as cotton, rayon, rarnie, jute and the like which can be impregnated with a liquid, dried, and cured.

The following examples are illustrative of the details of at least one method of practicing the present invention. All parts and percentages are by weight.

Example 1 A polymeric diethylene glycol-formaldehyde acetal was prepared essentially as described in U .8. Patent No. 2,786,081, using approximately equimolm quantities of diethylene glycol and paraforrnaldehyde (slight excess of the latter), a small amount of concentrated sulfuric acid as. the catalyst, ,and toluene as the solvent. Following removal of water and solvent, the reaction product was neutralized with alkali.

Aqueous solutions were prepared from the polymeric acetal and dimethylol ethyleneurea in the concentrations indicated in the following table. Each solution contained. 6%. magnesium chloride hexahydrate as a. cone densation'catalyst. Cotton print cloth was wet with these solutions and passed through The fabrics were dried at chlorite, bleaches (measured by the percentage of original breaking strength retained in the scorch test, American Association of Textile Chemists and Colorists test 69-1952) of the fabrics treated as described.

Treating Solution Percent of I Wrinkle original recovery strength Dimethylol Polymeric angle, retained in ethyleneacetal. degrees scorch urea, percent (warp+fill) test percent Samples of each of the above treated fabrics were submitted to 5 laundry cycles as described in the American Association of Textile Chemists and Colorists test 14-53. After laundering, the samples were again tested for wrinkle resistance and resistance to hypochlorite bleach. Results are shown in the following table.

Treating Solution Percent of Wrinkle original recovery strength D'unothylol Polymeric angle, retained in ethyleneacotal, degrees scorch urea, percent (warp+fill) test percent The superiority of the treatment using the mixed agents is shown by the higher wrinlde recovery when compared to the treatment using only the polymeric acetal, and the higher strength retention in the scorch test when compared to the treatment using dimethylol ethyleneurea alone. The treatment using the combined agents acquires a large part of the desirable features of each of the individual agents.

Example 2 Cotton printcloth was treated by the procedure described in Example 1, except that the treating solutions contained 1% zinc nitratehexahydrate and 0.1% acetic acid in place of 6% magnesium chloride hexahydrate. Wrinkle resistance and resistance to damage from hypo chlorite bleach, before and after 5 laundcrings, are shown in the following table.

Treating Solution Before I a-m1daring After Laundering Wrinkle Percent Wrinkle Percent Dimethylol Polyrecovery strength recovery strength ethyl' meric angle, retained angle, retained .enenrea, mm, degrees in scorch degrees in scorch percent percent (warph test (warp test a 7 248 107" 267 91 l. 5 7 10 262 104. 277 I 82 7 10 273 106 297 '96 7 0 2 108 283 50 Example 3 Aqueous solutions were prepared containing 5% dirnethylol ethyleneurea, 10% polymeric diethylene glycolforrnaldehyde acetal prepared as in Example 1, and. 1.5% polyethylene (added as an aqueous emulsion). One solution contained 6% magnesium chloride hexahydrate and another 1% zinc nitrate hexahydrate and 0.1% acetic ,acid. These solutions were usedr to treat cotton print cloth as described in Example 1. Properties of the treated fabrics, before and after 5 launderings, are shown the following table.

BeforeLaundoring After Laundering Metallic salt Wrinkle Percent Wrinkle Percent catalyst used recovery strength recovery strength a angle, retained angle, retained degrees in scorch degrees in search (warp test (warp test +fill) +fill) 21103 03); 271 97 277 91 oh 27s 83 278 82 Example 4 An acetal was prepared by the condensation of approxirnately equimolar quantities of glycerol and paraformaldehyde (slight excess of the latter), using a small amount of hydrochloric acid as the catalyst and heating the reaction mixture for 2 hours at C. Aqueous solutions were prepared containing 10% of this acetal, 7% dimethylol ethyleneurea and either 6% magnesium chloride hexahydrate, or 1.5% zinc nitrate hexahydrate and 0.15 acetic .acid. Cotton print cloth was treated with these solutions by the procedure described in Example 1. The wrinkle resistance and resistance to damage from hypochlorite bleach, before and after 5 launderings, are

We claim: 1. A process for treating a cellulosic textile material whereby said material is rendered durably wrinkleand muss-resistant and resistant to damaging effects from hypochlorite bleaching agents, which process comprises the following steps: impregnating said cellulosic textile material to a wet pickup of from about to with an aqueous solution comprising from 3 to 7% by weight of 5 dimethylol ethyleneurea, from 5 to 10% by weight of a polymeric acetal formed from formaldehyde and a polyhydroxy compound, and from 1 to 6% by weight of an acidic condensation catalyst; drying the impregnated material; and then curing it at a temperature of from about 10 to 4 i to C.

2. A process for treating a cellulosic textile material whereby said material is rendered durably Wrinkleand muss-resistant and resistant to damaging efiects from hypochlorite bleaching agents, which process comprises the following steps: impregnating said cellulosic textile material to a wet pickup of from about 70 to 80% with References Cited in the file of this patent UNITED STATES PATENTS 5 2,785,949 Kress Mar. 19, 1957 2,786,081 Kress Mar. 19, 1957 2,898,238 Van Loo et a1 Aug. 4, 1959 

1. A PROCESS FOR TREATING A CELLULOISIS TEXTILE MATERIAL WHEREBY SAID MATERIAL IS RENDERED DURABLY WRINKLE- AND MUSS-RESISTANT AND RESISTANT TO DAMAGING EFFECTS FROM HYPOCHLORITE BLEACHING AGENTS, WHICH PROCESS COMPRISES THE FOLLOWING STEPS: IMPREGNATING SAID CELLULOSIC TEXTILE MATERIAL TO A WET PICKUP OF FROM ABOUT 70 TO 80% WITH AN AQUEOUS SOLUTION COMPRISING FROM 3 TO 7% BY WEIGHT OF DIMETHYLOL ETHYLENEUREA, FROM 5 TO 10% BY WEIGHT OF A POLYMERIC ACETAL FORMED FROM FORMALDEHYDE AND A POLYHYDROXY COMPOUND, AND FROM 1 TO 6% BY WEIGHT OF AN ACIDIC CONDENSATION CATALYST; DRYING THE IMPREGNATED MATERIAL; AND THEN CURING IT AT A TEMPERATURE OF FROM ABOUT 130* TO 170*C. 